Photoelectric tone generator



July 23, 1963 T) J. BUITKUS 3,098,889

PHOTOELECTRIC TONE GENERATOR i la F|G.2 6 "WWW-H7477@ #L '0QlllHllllllllllllllllllllllllllllllllllllllllllllll@ 7 United StatesPatent Oli ice 3,5%,889 Patented July 23, 1963 3,098,889 PHOTGELECTRICTNlE GENERATOR rI'homas J. Bnitkus, 838 Lenox Ave., Waukegan, lll. FiledNov. 14, 1960, Ser. No. 68,973 3 Claims. (Cl. SLS- 1.18)

This invention relates generally to photoelectric tone generatingapparatus. More specifically, it relates to a `multiple-single toneaudio generator comprising a plurality of endless optical sound ltrackssuperimposed on` photoelectric cells together with means for translatingthe audio sources into continuous audible tones. This application is acontinuation-impart of my copendin-g application bearing Serial Number837,751, hled September 2, 1959, now abandoned.

Various types of photoelectric instruments have hitherto been disclosed.In the present ystate of the art, rotary discs or drums having opticalsound tracks depicted thereon serve to modulate light sources which arernade to impinge upon photoelectric cells or tubes spatially separatedfrom said 4discs or drums'. yIn such arrangements, only a single seriesof optical sound tracks may be accommodated along a given plane of eachrotating member since the light beams must by necessity pass completelythrough the discs or drums before reaching the light sensitive surfaceof the photoelectric cells or tubes.

It is a primary object of the present invention to prowide -a means -foraccommodating twice the number of optical sound tracks, not heretoforepossible on a given size disc or drum, lby vthe novel arrangement ofsuperimposing the optical sound tracks directly upon the light sensitivesurfaces of the photoelectric cells.

Another object of the present invention is to provide a self-containedaudio tone generator capable of the production of a large number ofvaried tones and timbres suitable for use in the manufacture of acompact and relatively inexpensive musical instrument.

`In the accompanying drawing, .forming a part of this application, andin which like numerals are used to designate like parts throughout thesame:

FIG. l is a fragmentary `face view of `one rotary discshapedphoto-electric cell showing optical sound tracks depicted thereon andrelationship of individual light sources thereto.

FIG. 2 is a cross-sectional view of the photoelectric tone generatordisc with rel-ated light sources taken along the line 2--2 of FIG. `1.

FIG. 3 is an enlarged, fragmentary detail view of two light sources,various parts associated therewith being broken away, with relatedoptical sound tracks and photoelectric cell shown in cross section.

EFIG. 4 is a diagrammatic plan view illustrating the basic components ofthe tone generator and their general rel-ation one to another.

Referring to FIGURES l and 2, a disc-shaped double faced photoelectriccell l is `shown having a plurality of endless, concentric optical soundtracks 2` residing upon both sides of said cell. Self-generating barrierlayer photoelectric cells of the selenium or silicon type may beemployed. It is to be understood, however, that the present invention isnot limited necessarily to the use of photoelectric cells of thephotovoltaic type as the term photoelectric used hereinafter shall alsoinclude photosensiti-ve cells of the photoconductive and photoemissivetypes. The light sensitive surface of the photoelectric cell l iscompletely covered or masked by an opaque light barrier 3 except forythe endless, concentric optical sound tracks 2 which appear within theopaque areas as transparent Waveform patterns exposing the lightsensitive surf-ace of the underlying photoelectric cell 1. The termoptical sound tracks referred to hereinafter shall be understood tocomprise endless bands in which opaque and transp-arent areas alternatein a manner so as to have a light modulating or interrupting function.Op- `tical sound tracks of the variable density .type 2A consisting ofvariations in the density or opacity of a track of constant width or avariable area type 2B consisting of Ivariations in Ithe width of exposedarea may be used. Such optical sound tracks may be formed from atransparent substance in which opaque areas are providedphotographically or otherwise or .by stamping or otherwise perfo-ratingan opaque material to provide for the passage of light. :Optical soundtracks may also be created by utilizing an electro-magnetically drivencutter to engrave variable area tracks into a transparent materialcovered by a thin opaque coating. Said optical sound tracks may containthe wavetforms characteristic of various orchestral instruments or mayconsist of synthetic waveforms. The width of the transparent portionsare limited in accordance with the iineness of the variations of thesound tracks `to permit proper scanning. It will be apparent that byvary-ing the size of the photoelectric cell, a greater or lesser numberof optical sound tracks may be accomm-odated thereon. The photoelectriccell disc `1 is provided with a hu-b 4 and setscrew 5 for attachment toshaft 6.

Positioned along one half of the diametrical portion of each side of thetone generator disc 1 is a ro-W of lamps 7 supported by arm 8 whichforms part of a fixed lampholder mounting bracket 9. A separate lamp 7(FIG. 3) is provided for each sound track. Each lamp is enclosed by ashield .10 provided with a light emitting slit 1.1 allor/ving only anarrow beam of light to be projected from the lamp onto its relatedsound track. The purpose of the shields is to prevent light fromstraying to adjacent tracks and sounding notes not intended. vOne of thewires l2 of each lam-p is grounded to the lamp-holder mounting bracket`9 While the other Wires are merged into a cable 13 .connected -to thecontrol circuit. The lamps are individually controlled by electricswitches or keys 14 permitting a single lamp or a plurality of same tobe illuminated. Said lamps may be of either the glow type orincandescent type. Incandescent lamps do not reach full brilliance orcomplete extinction instantly. This lag may be employed to advantage asthe resultant audio signal is characterized by a gradual increase and`decrease in volume which eliminates the abrupt sounding of notes.

lt Will be seen that whenever 4'a lamp is illuminated, a beam of lightis projected onto and traverses the sound track as the disc .1 isrotated. The light passing through the sound tracks I2 to the underlyingphotoelectric cell is thus made to vary periodically in intensitycorresponding to the Waveform patterns of transparency `and opacity insaid optical sound track. Since the electrical output of .thephotoelectric cell `1 is inuenced by the amount and intensity of radiantenergy received by its photosensitive area, a continuous electricalWaveform is thus generated corresponding to the light modulatingcharacter of the optical sound track. When several lamps are illuminatedsimultaneously, the light beams passing through their related opticalsound tracks results in the generation of a compound or compositewaveform by the photoelectric cell. It can be seen that each opticalsound track 4functions as a light modulator with 4the associatedphotoelectric cell translating the modulated light into electr-icalwaveforms.

A plurality of photoelectric tone discs 1 attached to shaft 6 in tandemare shown in FIG. 4. One end of shaft 6 is provided with a bearing 15while the other end is coupled to a synchronous electric motor I16 orthe like in order that the discs may be rotated at a constant speed.

The electrical output `of the photoelectric tone ldiscs 1 is removedfrom the `rotating members by conductors 17 which are connected toslip-rings 118 having brushes 19 Ibearing thereon. The audio amplifier20l and loudspeaker 21 serve to amplify andtransduce the electricalwaves into audible tones either singly or collectively.

While a disc-shaped photoelectric .cell in association twith opticalsound tracks has been chosen for illustrative purposes, it will beapparent the photoelectric cells in the shape of cylinders `and the likemay be substituted Without departing ,from the scope and intent of thepresent invention.

While this invention has been described With particular reference to theconstruction shown in the drawing and while various changes may be madein the detail construction, it shall be understood that such changesshall be Within the `spirit and `.scope of the present invention lasdefined by the appended claims.

Having thus described the present invention, what is now claimed as newand desired to be protected by Letters Patent of the United States ofAmerica is:

1. A photoelectric transducer comprising, in combination, asubstantially disc shaped photoelectric cell having a photosensitivearea on each face, a plurality of endless ,concentric `optical soundtracks ldepicted upon said photosensitive areas, llight sourcescoinciding with said optical )sound tracks and means lfor removingelectrical output of said photoelectric cell.

2. An audio tone generator comprising, in combination, a plurality ofrotatable disc shaped photoelectric cells having a photosensitive areaon both -faces of each cell, a plurality of endless concentric opticalsound tracks in contiguity with the photosensitive sur-face areas ofboth faces of each cell, means tfor projecting light beams through saidoptical sound tracks onto said photoelectric cells together with meansfor translating electrical output of said photoelectric cells intoaudible tones.

3. An audio tone generator comprising, in combination, a plurality ofdisc shaped .photoelec-tric cells axially mounted in tandem on a shaft,each of said cells having a photosensitive area on both oaces, a seriesof endless `concentric optical sound `tracks depicted upon `said photo'-sensitive areas, means for rotating said photoeleotric cells, individuallight sources coinciding with each optical sound track, switch keys forcontrolling said light sources, together with means or removingelectrical output 4of said photoelectric cells and translating same intoaudible tones.

References Cited in the file of this patent UNITED STATES PATENTS888,802 Hammer May 26, 1908 1,986,547 Winch Jan. 1, 1935 2,014,741 LestiSept. 17, 11935 2,142,391 IFuschi Jan. 3, 1939 2,494,943 Hook Jan. 17,`1950 2,513,109 Roth June 27, 1950

1. A PHOTOELECTRIC TRANSDUCER COMPRISING, IN COMBINATION, ASUBSTANTIALLY DISC SHAPED PHOTOELECTRIC CELL HAVING A PHOTOSENSITIVEAREA ON EACH FACE, A PLURALITY OF ENDLESS CONCENTRIC OPTICAL SOUNDTRACTS DEPICTED UPON SAID PHOTO